It seems to be important to distinguish between two kinds of knowing: the knowing that comes from listening to trusted sources, and the knowing that comes from seeing why the world couldn’t possibly be any other way.
Let’s imagine someone shows you a box with two gears partially sticking out of opposite sides:
At first, you don’t know what will happen if the gear sticking out on the left is rotated downward. It could send the right gear downward, or it could send it upward; it could have absolutely no effect whatsoever. If the person tells you that the result will be the right gear rotating downward, you’ll either take it on faith, or you won’t, depending on how confident they seem and how much you trust them.
If, on the other hand, you look inside the box yourself ...
... then you’ll gain a very different sort of confidence. It might take some work, but after a little thinking, you can know that the person’s claim is wrong. It doesn’t matter what sort of expertise they have, relative to you, or how much others respect their insight, or whether most people think you’re crazy for disagreeing with the established answer, because you can see how the gears must move. It would be deeply confusing for the other person to turn out to be right, in this case—it would violate your understanding of physics, similar to how an engineer who has spent some time understanding gyroscopes would be shocked if they suddenly started behaving the way a five-year-old expected them to.
There are two important takeaways, here. First, it’s important to recognize that it’s possible to achieve a “gears-level understanding” of any phenomenon, even if it might in practice be very difficult to achieve.
Second, you want to develop insight into whether or not you have it, in any particular case. For instance, you might find it confusing if turning a doorknob had no effect on the door opening, but it’s unlikely to violate your sense of reality. Does your System 1 seem to think that your car and your computer work by magic, and could just—stop working? Do your patterns of drive and motivation feel mysterious to you?
Gears-level understanding isn’t always a reasonable target, but all else being equal, having it is better than not, and seeking it is a good way to learn. It’s not the be-all-and-end-all, but it’s another lens to use when deciding whether or not you truly understand some aspect of the world around you.